#include <bits/stdc++.h>
using namespace std;

ifstream fin("text.in");
ofstream fout("text.out");

char ch;
int x, nrch, cuv;

int Litera(char ch)
{
    if (ch >= 'A' && ch <= 'Z') return 1;
    if (ch >= 'a' && ch <= 'z') return 1;
    return 0;
}

int main()
{
    while (fin.get(ch))
        if (Litera(ch) == 1)
            x++;
        else if (x > 0)
        {
            nrch += x;
            cuv++;
            x = 0;
        }
    if (x > 0)
    {
        nrch += x;
        cuv++;
    }
    if (cuv == 0) fout << "0\n";
    else fout << nrch / cuv << "\n";
    return 0;
}